114 SERIAL SECTION MOUNTING. 



" squeegee "). The sections are laid on it and pressed down lightly 

 with a brush (if they will bear it). The slide may then be warmed 

 for some minutes on a water-bath, and the paraffin removed with a 

 solvent. 



It is not necessary to warm the slide at all ; the paraffin can be 

 removed in the cold if desired by putting the slide into toluol, xylol, 

 or the like. But the slide must, in any case, be treated with alcohol 

 after removal of the paraffin, in order to get rid of the glycerin, 

 which will cause cloudiness if not perfectly removed. 



This method allows of the staining of sections on the slide with 

 perfect safety, both with alcoholic and aqueous stains, provided 

 they be not alkaline. 



According to my experience, the albumen method is absolutely 

 safe, provided that alkaline fluids be avoided in the after-treatment. 

 It has the defect that certain plasma stains (not chromatin stains) 

 colour the albumen very strongly, and cannot be removed from it, 

 and that sections are not expanded by it. 



It sometimes happens that the mixture after it has stood for some 

 time becomes turbid, and at last coagulates, passing into a caseous 

 state ; or it may undergo a hyaline coagulation, drying up like 

 amber. But up to the very last it does not in general lose its adhesive 

 properties. I have, however, found it to do so, after keeping for 

 five or six years, so that, to be on the safe side, it may be well to 

 make it up fresh every six months. 



HEIDENHAIN (Zeit. wiss. Mikr., xxii, 1905, p. 331) makes it up 

 with 1 grm. of blood albumen dissolved in 25 c.c. of water, and an 

 equal volume of 50 per cent, alcohol. 



188. The Albumen and Water Method (HENNEGUY, Journ. de 

 VAnat. et de la Physiol., 1891, p. 398). A drop of water is spread 

 on a slide painted with Mayer's white-of-egg mixture, the sections 

 are arranged on it, the whole is warmed (not to the melting-point 

 of the paraffin) until the sections flatten out ; the water is then 

 evaporated off at a temperature of about 40 C., and as soon as it 

 has sufficiently disappeared, which at that temperature will be in 

 about ten to fifteen minutes, the slide is further treated as described 

 last . 



This is a most valuable method. It is quicker than the water 

 method, and, for difficult material, safer. 



See also OHLMACHEB, Journ. Amer. Med. Assoc., April, 1893. 

 The so-called " Japanese " method, attributed to IKEDA by KEINKE 

 (Zeit. wiss. Mik., xii, 1895, p. 21), is merely that of HENNEGUY. 

 MANN (Anat. Ana., viii, 1893, p. 442) shakes up white of egg with 



